The purpose of this project is to evaluate and develop a variety of clinical applications for noninvasive ultrasound imaging to the diagnosis and treatment of impaired swallowing and speech and to evaluate the oropharyngeal structures (tongue, palate, floor muscles, hyoid, larynx, pharynx) in both normal and abnormal populations. This past year we have successfully developed a new three-dimensional ultrasound system for imaging the oropharynx. This system allows us to systematically track head and neck tumor growth, inflammatory changes in oral tissues, and soft tissue changes in the oropharynx resulting from concurrent radiation therapy, chemotherapy and surgery in patients with advanced head and neck tumors. We are collaborating with NIDCD and NCI in this application. We have collected long-term recovery (24 to 30 months) and morbidity data on our original 23 subjects and an additional 11 patients with head and neck tumors. The natural evolution of swallowing function and course of recovery of oral motor function and return of eating behaviors is now under study. An outcome matrix is being used to chart dependence/independence during eating, swallowing function and oral safety. Analysis of the effects of viscosity and volume on hyoid motion in 31 normals revealed that there were significant effects of the thickness of the bolus on hyoid motion. Age and gender differences were also found during swallowing that suggest anatomical variations, sensory acuity and muscle force changes occur with normal aging that can effect swallowing kinematics.